Rotary vacuum drum dryers were originally developed as a means to separate solids from a slurry. Vacuum drum dryers are one of the first industrial systems created to separate solids from liquids, and are prevalent in diverse industries from food production, wine and distilled spirits production, and the production of various materials for the construction sector. In basic vacuum drum dryers, the level of the slurry tank with respect to the rotating drum and the rotational speed of the drum are the two parameters most commonly used to make performance adjustments.